JPH06290547A - High-speed data transferring method - Google Patents

Abstract

PURPOSE:To eliminate the delay of data transfer due to the fact that the seek operation of a head is performed by moving back and forth between normal sectors in consecutive sectors and replacing sectors when defective sectors are included in the consecutive sectors when the read/write of the consecutive sectors is demmanded from a host computer to a disk device having a function replacing defective sectors with normal sectors in replacing sector area on the disk. CONSTITUTION:At the time of starting power source, a controller 4 copies the content of replacing sectors on the disk to RAM replacing area 3. When the controller 4 receives the read/write command to the consecutive sectors from the host computer 1 and when the defective sectors are included in sectors, the controller 4 performs the read/write processions to normal sectors in respective consecutive sectors at first and next performs the read/write processions as to replacing sectors of defective sectors to respective individual sector areas in the RAM replacing sector area 3 in stead of the disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device such as a magnetic disk device or a magneto-optical disk device having a function of replacing a defective sector on the disk with another normal sector in the replacement sector area on the disk. Based on a read / write command of a continuous sector area from a host computer (also simply abbreviated as a host), the disk device performs a seek operation of a head that reciprocates between a normal sector area and an alternate sector area, thereby determining the data transfer rate. The present invention relates to a high-speed data transfer method of a disk device for preventing deterioration and performing high-speed data transfer.

In the following figures, the same reference numerals indicate the same or corresponding parts.

[0003]

2. Description of the Related Art In general, a host computer reads / writes data from / to a continuous sector area of a disk device by instructing the disk device of a leading sector number and the number of continuous sectors to be read / written. The controller that interfaces between the host computer and the disk device performs read / write on the disk according to the instruction of the command received from the host side.

In the disk device, a defective sector (that is, a sector that is defective and cannot be read / written) is replaced with a replacement sector secured in a specific area at the time of initialization. FIG. 5 is an explanatory diagram of sectors on the disk surface. In the figure, reference numeral 51 denotes a normal sector area, in which the sectors are arranged in order from circle 1 to circle 12. However, for example, circle 4 and circle 7 are defective sectors 52. D1
An area 53 composed of Dn sectors is a replacement information area in which replacement sectors (replacement sectors) for such defective sectors are secured. In this example, circles 4 and 7 are defective sectors 52.
Are replaced by replacement sectors D1 and D2, respectively, and replacement information (that is, the address of the replacement source sector and the data to be written therein) is written in each replacement sector.

By the way, when the sector to be read / written has a defective sector, the controller performs the following operation, for example, in order to read / write continuous sectors including the replacement sector. FIG. 6 is a flowchart of the read / write processing of such a conventional disk controller, and S1 to S7 indicate the steps. That is, when a read / write command is received from the host after the power is turned on (S1, S2), the head sector number (address) and the number of sectors of consecutive sectors to be read / written are confirmed (S3), and the corresponding normal sector is read. After seeking to the area 51, read / write is performed on a normal continuous sector up to immediately before the defective sector 52 (S4), and if there is a defective sector, the head is sought to the replacement sector (S5, S6). Read / write. After that,
The head is returned to the normal sector immediately after the original defective sector (S4), and the same operation is continued.

[0006]

However, in such a conventional read / write method, every time there is a defective sector, the seek operation of the head to the normal sector at the replacement destination occurs, and the data read / write as a whole is performed. There is a problem that the speed becomes slow. That is, when a defective sector is included in the continuous sectors to be read / written, the head reciprocates between the normal sector area 51 and the replacement sector area 53 by the number of defective sectors. / Write speed becomes slow.

Therefore, it is an object of the present invention to provide a high-speed data transfer method for a disk device that solves such a problem.

[0008]

In order to solve the above-mentioned problems, in the high-speed data transfer method according to claim 1, a defective sector which is defective and readable and writable on the disk (52, etc.) is replaced with a replacement sector on the disk. In a disk device having a function of replacing another normal sector in an area (such as the replacement information area 53), at least the address data of the replacement source sector and the data of the replacement source sector in the replacement sector area on the disk are RAM In the spare sector area (3 etc.) prepared in advance, and read / write data from / to the spare sector area of the disk by a read / write command from the host computer (1 etc.)
The write corresponds to the R sector corresponding to the replacement sector area of the disk.
By performing access to the alternate sector area in the AM, the seek operation of the head is reduced to achieve high-speed data transfer.

Further, in the high speed data transfer method according to claim 2,
The high-speed data transfer method according to claim 1, wherein when the disk device rewrites the replacement sector area in the RAM based on a write command from a host computer,
After the command is finished, the same data as the data rewritten in the RAM is overwritten in the spare sector area on the disk corresponding to the spare sector area.

[0010]

Operation: The replacement information area 5 on the disk in the disk device
A RAM area for copying the contents of 3 is provided, and when the power is turned on, the contents of the replacement information area are read and stored in the replacement sector area of this RAM, and it is necessary to access the replacement sector when reading / writing the disk thereafter. In this case, the alternate sector area of the RAM is accessed to reduce the seek operation and transfer the data at high speed.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is an embodiment of the present invention, and is a block diagram showing the configuration of a system for reading and writing to a disk. In the figure, 1 is a high-order host computer, 2
Is a disk device, 3 is a replacement sector area of RAM, 4 is a controller (control unit), 5 is a host interface unit,
6 is a buffer manager, 7 is a controller buffer, and 8 is a disk drive. The host computer 1 is connected to the disk device 2 via the host interface unit 5 at the time of reading / writing, and when reading / writing a continuous sector area of the disk, the head sector number for reading / writing from / to the disk device 2 is set. Include the number of sectors in the read / write command to instruct. At the time of writing, write data is sent to the disk device 2 following the write command, and at the time of reading, the read command is output and then the sector data read from the disk device 2 is received. The replacement sector area 3 of the RAM is a portion added by the present invention.

FIG. 2 shows a configuration example of the replacement sector area 3 of this RAM. That is, the replacement sector area 3 is composed of n areas R1 to Rn corresponding to the n replacement sectors D1 to Dn in the replacement information area 53 of FIG. Each is composed of management information (address) 11 for the corresponding replacement sector and data 12 of the replacement sector.

FIG. 3 shows an example of the structure of the controller buffer 7, which is a temporary storage location for read / write data to the disk. FIG. 4 is a flowchart for explaining the operation of the controller of FIG. 1, and S11 to S20 show the steps. In the configuration of FIG. 1, the host computer 1 and the disk device 2 exchange commands and data by a handshake method for each byte. The read / write operation from the power-on to the disk in this configuration will be described below with reference to FIGS. 1 to 3 and 5 and the flowchart of FIG.

When power is turned on: As shown in FIG.
Similar to the disc, the M pieces of n pieces of replacement information (the replacement source address 11 and the data 1 to be written there) are stored in advance.
2) The dedicated replacement sector area 3 is secured. After the power is turned on (S11), the replacement information for each defective sector (D1 to Dn in FIG. 5) in the replacement information area 53 of the disk must be written for each replacement sector in the replacement sector area 3 of the RAM before entering the command waiting state. A procedure for copying to the area (R1 to Rn in FIG. 2) is incorporated. That is, in the initial command wait, the same contents as the replacement sectors D1 to Dn on the disk are copied to the individual areas R1 to Rn of the replacement sector area 3 of the RAM (S12).

Read of continuous sectors: circle 4 in FIG.
And the circle 7 are defective sectors 52 and are replaced by the replacement sectors D1 and D2, respectively, the head when receiving a command from the host computer 1 to continuously read the sectors 1 to 12 And the flow of data will be described. When a command is received (S1
3) The controller 4 confirms the start address and the number of sectors of continuous sectors to be read / written (S14), first seeks the head to a normal sector, and makes the data of the sector excluding the defective sector correspond to the controller buffer 7. Address (B1 to B3, B5, B6, B8 to B1 in FIG. 3)
Write in 2). Next, from the individual sector areas (R1 and R2 in this example) of the replacement sector area 3 of the RAM, the sector data for defective sectors circles 4 and 7 in FIG. 5 are transferred to the corresponding addresses (B4 in FIG. 3) of the controller buffer 7. B7)
(S16, S17). As a result, data is written in the controller buffer 7 in the order of information series. Next, the controller 4 uses this controller buffer 7
The continuous information sequence in the above is sent to the host computer 1 via the buffer manager 6 and the host interface unit 5.

Write of consecutive sectors: circle 4 in FIG.
And circle 7 are defective sectors, and replacement sectors D1 and D2, respectively.
The following will describe the movement of the head and the flow of data when a command for continuously writing the sectors from circle 1 to circle 12 is received from the host computer 1 in the case where the data is exchanged for. When the command is received (S13),
Following this command, the controller (control unit) 4 once writes the continuous sector data output from the host computer 1 to each address area (B1 to B12 in FIG. 3) of the controller buffer 7 via the buffer manager 6. . Next, the controller 4 first seeks the head in the normal sector area 51, and sequentially addresses corresponding sectors (B1 to B3, B5, B6, B8 to B8 in FIG. 3) of the controller buffer 7 for each sector except the defective sector 52. The data of B12) is written (S15). Next, the sector data corresponding to the defective sector is stored in the replacement sector area 3 of the RAM at the corresponding addresses (B4 and B in FIG. 3) of the controller buffer 7.
Transfer from 7) (S16, S17). And host 1
Immediately after the end of the command (S18), if there is a change in the replacement sector area 3 of the RAM (S19, branch Y), that is, if there is a replacement sector in the written range, the updated RAM contents are replaced with the replacement sector of the disk. The area 53 is overwritten and the replacement information on the disc is also updated (S20).

[0017]

According to the present invention, when the power is turned on, the controller of the disk device reads the replacement sector information on the disk into the RAM, and thereafter, the replacement sector is accessed to the RAM. That is, when the controller receives a read / write command from the host computer, it first reads / writes only the normal sector, and then reads / writes the replacement sector copied to the RAM only when the replacement sector exists. . When the content of the replacement sector of the RAM is updated during the execution of the write command, the replacement area of the disk is also updated immediately after the end of the command. As described above, in the present invention, the access to the replacement area is R
Since it is performed by AM, data transfer can be performed while the movement of the slow-moving head is minimized. As a result, high-speed data transfer with less seek operation becomes possible.

An example in which the present invention is effective will be introduced. Data processing in an external device (host computer or other peripheral device) connected from the controller of the disk device via a SCSI bus or the like has a time constraint regarding serial data transfer because the sequencer circuit is used. If it is large, the conventional method may cause a malfunction. Data must be transferred at high speed (without interruption) to such a system, and the effectiveness of the present invention is considered to be exerted.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a system as an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a replacement sector area of the RAM of FIG.

FIG. 3 is a diagram showing a configuration example of a controller buffer in FIG.

4 is a flowchart for explaining the operation of the disk device shown in FIG.

FIG. 5 is an explanatory diagram of a sector area on the disk surface.

FIG. 6 is a flowchart for explaining the operation of a conventional disk device.

[Explanation of symbols]

 1 host computer 2 disk device 3 replacement sector area of RAM 4 controller (control section) 5 host interface section 6 buffer manager 7 controller buffer 8 disk drive 11 address 12 data 51 normal sector area 52 defective sector 53 replacement information area

Claims (2)

[Claims] 1. A disk device having a function of replacing a defective readable / writable defective sector on a disk with another normal sector of an alternate sector area on the disk,
When power is turned on, at least the address data of the replacement source sector and the data of the replacement source sector in the replacement sector area on the disk are copied to the replacement sector area prepared in advance in the RAM and the disk is read / written by the host computer. The data read / write from / to the replacement sector area of the disk is performed by accessing the replacement sector area in the RAM corresponding to the replacement sector area of the disk, and high-speed data transfer is performed by reducing the seek operation of the head. A high-speed data transfer method for a disk device characterized. 2. The high-speed data transfer method according to claim 1, wherein when the disk device rewrites the replacement sector area in the RAM based on a write command from a host computer, the replacement sector is written after the command is completed. A high-speed data transfer method for a disk device, characterized in that the same data as the data rewritten in the RAM is overwritten in an alternate sector area on the disk corresponding to the area.